From d235e2c6a5788ec4a6cff15a16f56b38a3876a0d Mon Sep 17 00:00:00 2001 From: Determinant Date: Sun, 28 Jun 2020 14:47:41 -0400 Subject: ... --- accounts/keystore/keystore.go | 495 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 495 insertions(+) create mode 100644 accounts/keystore/keystore.go (limited to 'accounts/keystore/keystore.go') diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go new file mode 100644 index 0000000..a3ce33f --- /dev/null +++ b/accounts/keystore/keystore.go @@ -0,0 +1,495 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +// Package keystore implements encrypted storage of secp256k1 private keys. +// +// Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification. +// See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information. +package keystore + +import ( + "crypto/ecdsa" + crand "crypto/rand" + "errors" + "fmt" + "math/big" + "os" + "path/filepath" + "reflect" + "runtime" + "sync" + "time" + + "github.com/ava-labs/coreth/accounts" + "github.com/ava-labs/coreth/core/types" + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/crypto" + "github.com/ava-labs/go-ethereum/event" +) + +var ( + ErrLocked = accounts.NewAuthNeededError("password or unlock") + ErrNoMatch = errors.New("no key for given address or file") + ErrDecrypt = errors.New("could not decrypt key with given password") +) + +// KeyStoreType is the reflect type of a keystore backend. +var KeyStoreType = reflect.TypeOf(&KeyStore{}) + +// KeyStoreScheme is the protocol scheme prefixing account and wallet URLs. +const KeyStoreScheme = "keystore" + +// Maximum time between wallet refreshes (if filesystem notifications don't work). +const walletRefreshCycle = 3 * time.Second + +// KeyStore manages a key storage directory on disk. +type KeyStore struct { + storage keyStore // Storage backend, might be cleartext or encrypted + cache *accountCache // In-memory account cache over the filesystem storage + changes chan struct{} // Channel receiving change notifications from the cache + unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys) + + wallets []accounts.Wallet // Wallet wrappers around the individual key files + updateFeed event.Feed // Event feed to notify wallet additions/removals + updateScope event.SubscriptionScope // Subscription scope tracking current live listeners + updating bool // Whether the event notification loop is running + + mu sync.RWMutex +} + +type unlocked struct { + *Key + abort chan struct{} +} + +// NewKeyStore creates a keystore for the given directory. +func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore { + keydir, _ = filepath.Abs(keydir) + ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}} + ks.init(keydir) + return ks +} + +// NewPlaintextKeyStore creates a keystore for the given directory. +// Deprecated: Use NewKeyStore. +func NewPlaintextKeyStore(keydir string) *KeyStore { + keydir, _ = filepath.Abs(keydir) + ks := &KeyStore{storage: &keyStorePlain{keydir}} + ks.init(keydir) + return ks +} + +func (ks *KeyStore) init(keydir string) { + // Lock the mutex since the account cache might call back with events + ks.mu.Lock() + defer ks.mu.Unlock() + + // Initialize the set of unlocked keys and the account cache + ks.unlocked = make(map[common.Address]*unlocked) + ks.cache, ks.changes = newAccountCache(keydir) + + // TODO: In order for this finalizer to work, there must be no references + // to ks. addressCache doesn't keep a reference but unlocked keys do, + // so the finalizer will not trigger until all timed unlocks have expired. + runtime.SetFinalizer(ks, func(m *KeyStore) { + m.cache.close() + }) + // Create the initial list of wallets from the cache + accs := ks.cache.accounts() + ks.wallets = make([]accounts.Wallet, len(accs)) + for i := 0; i < len(accs); i++ { + ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks} + } +} + +// Wallets implements accounts.Backend, returning all single-key wallets from the +// keystore directory. +func (ks *KeyStore) Wallets() []accounts.Wallet { + // Make sure the list of wallets is in sync with the account cache + ks.refreshWallets() + + ks.mu.RLock() + defer ks.mu.RUnlock() + + cpy := make([]accounts.Wallet, len(ks.wallets)) + copy(cpy, ks.wallets) + return cpy +} + +// refreshWallets retrieves the current account list and based on that does any +// necessary wallet refreshes. +func (ks *KeyStore) refreshWallets() { + // Retrieve the current list of accounts + ks.mu.Lock() + accs := ks.cache.accounts() + + // Transform the current list of wallets into the new one + var ( + wallets = make([]accounts.Wallet, 0, len(accs)) + events []accounts.WalletEvent + ) + + for _, account := range accs { + // Drop wallets while they were in front of the next account + for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 { + events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped}) + ks.wallets = ks.wallets[1:] + } + // If there are no more wallets or the account is before the next, wrap new wallet + if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 { + wallet := &keystoreWallet{account: account, keystore: ks} + + events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived}) + wallets = append(wallets, wallet) + continue + } + // If the account is the same as the first wallet, keep it + if ks.wallets[0].Accounts()[0] == account { + wallets = append(wallets, ks.wallets[0]) + ks.wallets = ks.wallets[1:] + continue + } + } + // Drop any leftover wallets and set the new batch + for _, wallet := range ks.wallets { + events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped}) + } + ks.wallets = wallets + ks.mu.Unlock() + + // Fire all wallet events and return + for _, event := range events { + ks.updateFeed.Send(event) + } +} + +// Subscribe implements accounts.Backend, creating an async subscription to +// receive notifications on the addition or removal of keystore wallets. +func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription { + // We need the mutex to reliably start/stop the update loop + ks.mu.Lock() + defer ks.mu.Unlock() + + // Subscribe the caller and track the subscriber count + sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink)) + + // Subscribers require an active notification loop, start it + if !ks.updating { + ks.updating = true + go ks.updater() + } + return sub +} + +// updater is responsible for maintaining an up-to-date list of wallets stored in +// the keystore, and for firing wallet addition/removal events. It listens for +// account change events from the underlying account cache, and also periodically +// forces a manual refresh (only triggers for systems where the filesystem notifier +// is not running). +func (ks *KeyStore) updater() { + for { + // Wait for an account update or a refresh timeout + select { + case <-ks.changes: + case <-time.After(walletRefreshCycle): + } + // Run the wallet refresher + ks.refreshWallets() + + // If all our subscribers left, stop the updater + ks.mu.Lock() + if ks.updateScope.Count() == 0 { + ks.updating = false + ks.mu.Unlock() + return + } + ks.mu.Unlock() + } +} + +// HasAddress reports whether a key with the given address is present. +func (ks *KeyStore) HasAddress(addr common.Address) bool { + return ks.cache.hasAddress(addr) +} + +// Accounts returns all key files present in the directory. +func (ks *KeyStore) Accounts() []accounts.Account { + return ks.cache.accounts() +} + +// Delete deletes the key matched by account if the passphrase is correct. +// If the account contains no filename, the address must match a unique key. +func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error { + // Decrypting the key isn't really necessary, but we do + // it anyway to check the password and zero out the key + // immediately afterwards. + a, key, err := ks.getDecryptedKey(a, passphrase) + if key != nil { + zeroKey(key.PrivateKey) + } + if err != nil { + return err + } + // The order is crucial here. The key is dropped from the + // cache after the file is gone so that a reload happening in + // between won't insert it into the cache again. + err = os.Remove(a.URL.Path) + if err == nil { + ks.cache.delete(a) + ks.refreshWallets() + } + return err +} + +// SignHash calculates a ECDSA signature for the given hash. The produced +// signature is in the [R || S || V] format where V is 0 or 1. +func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) { + // Look up the key to sign with and abort if it cannot be found + ks.mu.RLock() + defer ks.mu.RUnlock() + + unlockedKey, found := ks.unlocked[a.Address] + if !found { + return nil, ErrLocked + } + // Sign the hash using plain ECDSA operations + return crypto.Sign(hash, unlockedKey.PrivateKey) +} + +// SignTx signs the given transaction with the requested account. +func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) { + // Look up the key to sign with and abort if it cannot be found + ks.mu.RLock() + defer ks.mu.RUnlock() + + unlockedKey, found := ks.unlocked[a.Address] + if !found { + return nil, ErrLocked + } + // Depending on the presence of the chain ID, sign with EIP155 or homestead + if chainID != nil { + return types.SignTx(tx, types.NewEIP155Signer(chainID), unlockedKey.PrivateKey) + } + return types.SignTx(tx, types.HomesteadSigner{}, unlockedKey.PrivateKey) +} + +// SignHashWithPassphrase signs hash if the private key matching the given address +// can be decrypted with the given passphrase. The produced signature is in the +// [R || S || V] format where V is 0 or 1. +func (ks *KeyStore) SignHashWithPassphrase(a accounts.Account, passphrase string, hash []byte) (signature []byte, err error) { + _, key, err := ks.getDecryptedKey(a, passphrase) + if err != nil { + return nil, err + } + defer zeroKey(key.PrivateKey) + return crypto.Sign(hash, key.PrivateKey) +} + +// SignTxWithPassphrase signs the transaction if the private key matching the +// given address can be decrypted with the given passphrase. +func (ks *KeyStore) SignTxWithPassphrase(a accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) { + _, key, err := ks.getDecryptedKey(a, passphrase) + if err != nil { + return nil, err + } + defer zeroKey(key.PrivateKey) + + // Depending on the presence of the chain ID, sign with EIP155 or homestead + if chainID != nil { + return types.SignTx(tx, types.NewEIP155Signer(chainID), key.PrivateKey) + } + return types.SignTx(tx, types.HomesteadSigner{}, key.PrivateKey) +} + +// Unlock unlocks the given account indefinitely. +func (ks *KeyStore) Unlock(a accounts.Account, passphrase string) error { + return ks.TimedUnlock(a, passphrase, 0) +} + +// Lock removes the private key with the given address from memory. +func (ks *KeyStore) Lock(addr common.Address) error { + ks.mu.Lock() + if unl, found := ks.unlocked[addr]; found { + ks.mu.Unlock() + ks.expire(addr, unl, time.Duration(0)*time.Nanosecond) + } else { + ks.mu.Unlock() + } + return nil +} + +// TimedUnlock unlocks the given account with the passphrase. The account +// stays unlocked for the duration of timeout. A timeout of 0 unlocks the account +// until the program exits. The account must match a unique key file. +// +// If the account address is already unlocked for a duration, TimedUnlock extends or +// shortens the active unlock timeout. If the address was previously unlocked +// indefinitely the timeout is not altered. +func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout time.Duration) error { + a, key, err := ks.getDecryptedKey(a, passphrase) + if err != nil { + return err + } + + ks.mu.Lock() + defer ks.mu.Unlock() + u, found := ks.unlocked[a.Address] + if found { + if u.abort == nil { + // The address was unlocked indefinitely, so unlocking + // it with a timeout would be confusing. + zeroKey(key.PrivateKey) + return nil + } + // Terminate the expire goroutine and replace it below. + close(u.abort) + } + if timeout > 0 { + u = &unlocked{Key: key, abort: make(chan struct{})} + go ks.expire(a.Address, u, timeout) + } else { + u = &unlocked{Key: key} + } + ks.unlocked[a.Address] = u + return nil +} + +// Find resolves the given account into a unique entry in the keystore. +func (ks *KeyStore) Find(a accounts.Account) (accounts.Account, error) { + ks.cache.maybeReload() + ks.cache.mu.Lock() + a, err := ks.cache.find(a) + ks.cache.mu.Unlock() + return a, err +} + +func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.Account, *Key, error) { + a, err := ks.Find(a) + if err != nil { + return a, nil, err + } + key, err := ks.storage.GetKey(a.Address, a.URL.Path, auth) + return a, key, err +} + +func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Duration) { + t := time.NewTimer(timeout) + defer t.Stop() + select { + case <-u.abort: + // just quit + case <-t.C: + ks.mu.Lock() + // only drop if it's still the same key instance that dropLater + // was launched with. we can check that using pointer equality + // because the map stores a new pointer every time the key is + // unlocked. + if ks.unlocked[addr] == u { + zeroKey(u.PrivateKey) + delete(ks.unlocked, addr) + } + ks.mu.Unlock() + } +} + +// NewAccount generates a new key and stores it into the key directory, +// encrypting it with the passphrase. +func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) { + _, account, err := storeNewKey(ks.storage, crand.Reader, passphrase) + if err != nil { + return accounts.Account{}, err + } + // Add the account to the cache immediately rather + // than waiting for file system notifications to pick it up. + ks.cache.add(account) + ks.refreshWallets() + return account, nil +} + +// Export exports as a JSON key, encrypted with newPassphrase. +func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string) (keyJSON []byte, err error) { + _, key, err := ks.getDecryptedKey(a, passphrase) + if err != nil { + return nil, err + } + var N, P int + if store, ok := ks.storage.(*keyStorePassphrase); ok { + N, P = store.scryptN, store.scryptP + } else { + N, P = StandardScryptN, StandardScryptP + } + return EncryptKey(key, newPassphrase, N, P) +} + +// Import stores the given encrypted JSON key into the key directory. +func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (accounts.Account, error) { + key, err := DecryptKey(keyJSON, passphrase) + if key != nil && key.PrivateKey != nil { + defer zeroKey(key.PrivateKey) + } + if err != nil { + return accounts.Account{}, err + } + return ks.importKey(key, newPassphrase) +} + +// ImportECDSA stores the given key into the key directory, encrypting it with the passphrase. +func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (accounts.Account, error) { + key := newKeyFromECDSA(priv) + if ks.cache.hasAddress(key.Address) { + return accounts.Account{}, fmt.Errorf("account already exists") + } + return ks.importKey(key, passphrase) +} + +func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) { + a := accounts.Account{Address: key.Address, URL: accounts.URL{Scheme: KeyStoreScheme, Path: ks.storage.JoinPath(keyFileName(key.Address))}} + if err := ks.storage.StoreKey(a.URL.Path, key, passphrase); err != nil { + return accounts.Account{}, err + } + ks.cache.add(a) + ks.refreshWallets() + return a, nil +} + +// Update changes the passphrase of an existing account. +func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string) error { + a, key, err := ks.getDecryptedKey(a, passphrase) + if err != nil { + return err + } + return ks.storage.StoreKey(a.URL.Path, key, newPassphrase) +} + +// ImportPreSaleKey decrypts the given Ethereum presale wallet and stores +// a key file in the key directory. The key file is encrypted with the same passphrase. +func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) { + a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase) + if err != nil { + return a, err + } + ks.cache.add(a) + ks.refreshWallets() + return a, nil +} + +// zeroKey zeroes a private key in memory. +func zeroKey(k *ecdsa.PrivateKey) { + b := k.D.Bits() + for i := range b { + b[i] = 0 + } +} -- cgit v1.2.3